Pump discharge fitting



March 23, 1,948. R. G. BERRY PUMP DISCHARGE FITTING Flled May 15, 1944v MEW/fm? FIGHE.

F l G. 3

. INVENTOR. RUSSELL G. BERRY F IG'. 5.

Patented Mar. 23 1948 PUMP DISCHARGE FITTING 'Russell G. Berry, Maplewood, Mo., assignor to A l Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application May 15, 1944, Serial No. 535,644'

3 Claims.

to utilize substantially lessfuel than that normally supplied by the pump and Where the carburetor inlet valve frequently closes entirely, even though the pump continues to operate.

In a co-pending application, Serial No. 473,683, filed January 27, 1943, now Patent No. 2,394,860, in the name of Alfred C. Korte, there is illustrated a centrifugal fuel pump which is operated at a substantially constant speed by an electric motor. In order to use this pump with engines varying Widely in capacity and, consequently, fuel requirements, it is necessary to limit the pump output and reduce the maximum pressure produced. Otherwise, the carburetor float valve, when closed, will be subjected to excessive pressures which will cause the float to sink deeper in the constant level chamber and, accordingly, raise the fuel level.

It is an object of the present invention to provide a restriction and by-pass fitting which can be readily inserted in the fuel connection between the pump and carburetor and which will accomplish this purpose.

When such a fitting is used, it is merely necessary to replace this part with a different one in order to adapt the pump for .use with an engine and carburetor having substantially different fuel requirements.

In the accompanying drawing which illustrates the invention,

Fig. 1 is a View of an electric fuel pump and carburetor constant level chamber with the novel fitting applied to the connection therebetween, illustrated diagrammatically.

Fig. 2 is an enlarged upper end view of the fitting.

Fig. 3 is a cross section of the fitting.

Fig. 4 is a top view of a modified form of fitting.

Fig. 5 is a section through the fitting in Fig. 4.

The pump in Fig. 1 is operated by electric motor II! and includes a centrifugal impeller II located in voluted casing I2 and at the lower end of motor shaft I 3. The entire motor and pump unit is normally submerged in the fuel tank and is connected by tubing I4 to .boss I5 forming the fuel inlet of carburetor constant level chamber I5. A valve seat I1 in boss I 5 receives needle valve I8 controlled by fioat I9 so as to maintain a substantially constant level of fuel in bowl I6. Fuel is supplied from bowl I6 to the carburetor in a well known manner through metering jet 20 and upwardly inclined fuel passage 2 I.

to a particular engine and carburetor.

A boss 23'forms the fuel outlet connection of the pump. To this boss there is threadedly attached the novel fitting, generally indicated at 24, to which, in turn, is connected tubing It. The fitting, as best shown in Figs. 2 and 3, includes an internal, apertured web 25 forming a restricted delivery orifice 26, anda fixed orifice 2i, located just posterior to restriction 2t, which by-passes a portion of the pumped liquidback into the fuel tank.

In operation, it is intended that fitting 24 be used where the normal output of the pump is substantially greater than the normal requirement of the carburetor. Restriction 2t and bypass 2l are so calibrated and proportioned that the pump output and the load thereon are reduced, accordingly. Furthermore, the restriction and by-pass also cooperate to limit the maximum pressure in tube connection Ill at times when float valve I8 is closed While the pump continues to operate. The restriction and by-pass must be calibrated for each different pump and'carburetor installation, but it is only necessary to provide the proper fitting in order to adapt a given pump The fitting is a relatively inexpensive part, while the cost of providing a large number of different pumps might be prohibitive. It is especially adapted for use with a centrifugal type of pump, since the restricted delivery and by-pass orifices have the effect of reducing the delivery and, consequently, `the load on the pump at all times.

The current required, thus, is reduced and operation made more economical.

In the modification in Figs. 4 and 5, a fixed restriction is provided at 26, as in the preferred form, but by-pass 21a is a threaded plug 3|. The functioning of this form. is substantially the same as that of the previous form, except that no fuel will be by-passed until sufficient pressure has been :built up to unseat check ball 3G.

The invention may be modified in various respects as will occur to those skilled in the art, and exclusive use of all modifications as come within the scope of the appended claims is contemplated.

I claim:

l. In combination, a liquid pump, a device having a connection thereto for norm ally using substantially less of the pumped liquid than the pump is constructed to supply, valve means to intermittently open and Close said connection to Y 3 maximum rate of ow maximum required by said device and to limit the maximum pressure in said connection when said valve is closed.

2. In combination, a substantially constant speed, centrifugal pump, a device having a connectionwitnsaid Vpump for normally utilizing less nqudxtilain; pump is constructed to supply, a yildably seating valv for intermittently opening and closing-said connection to said deof pumped liquid to the vice, and a replaceable fitting interposed between said pump and said device comprising aV tubular" part having a flow limiting restriction and ar restricted relief by-pass orice, said restriction and by-pass being proportioned with' relation to each other and to the pump capacity and normal requirements of said device to r'educe'themaxinium fuel supply when said valve is open to the maximum required and to limit the pressurev in said 'a' constant speed, centriftor having a fuel inlet y v e said pump being Artecl'- t" supply substantially more Vfuel ttiin" theV said carburetor is designed to iiir; *a* replaceable vfitting unit in said itii including a'- vfi'iied fuel delivery restricltionA and Ya relief Vby-pass restriction posterior tosai delivery restriction, said restrictions being calibrated and proportioned to reduce the -fuel supply, when said oat valve is open, substantially to that required by said carburetor and to Y limit the maximum pressure in said connection, when said valve is closed, to'that which said float valve is designed to resist Without altering the constant level of fuel in'said carburetor, said bypass restriction: also functioning to' reduce the pump delivery and consequently the load thereon when said carburetor valve is closed.

RUSSELL G. BERRY.

REFERENCES CITED The 'follvvingl references are of record in the fl-eot this patent: Y

UNITED STATES PATENTS 

